Any help would be much appreciated. I just bought a 16" electric cooling fan and a new radiator for my 56 chevy. I am running a 350 sbc. The fan does not have anything but bare wires coming out of it, and I am trying to figure out how to proceed. Should I use a thermostat switch
? and at what temp is the motor running at optimum? I was told I should have a relay, should I? and what would that do? Thanks for your input!

you will need a temp switch, this can be bought at any good auto parts dealer if you tell them what you are doing, if you want the switch to last you need to wire it to a relay and let the relay take the fan load.

On my Ranchero I run a mechanical flex fan as primary and the electric when stuck in So. Calif. traffic. I also wired a very small amber light into the electric fan that lights when the electric fan is on.

[ March 15, 2003: Message edited by: RAW ]</p>

__________________
Looking for the right '57 Ranchero for a "keeper" this time.

Definitely use a relay to protect the thermostatic switch. The fan draws high current which is too much for the thermostat. I get a nice small 2P2T black plastic relay from my auto parts store, I think made by Bosch. Inexpensive, easy to mount and has spade terminals. Circuit is,

1. Run black wire on fan to ground.
2. Run colored wire on fan to open pole on relay.
3. Run hot wire from fuse block to other other side of pole on relay.
4. Run one side of temperature switch to ground.
5. Run other side of temperature switch to one pole on the relay actuating coil.
6. Run jumper from terminal in step 3. to other pole on the relay actuating coil.
7. Optional - if you want to bypass the temperature switch, install an on-off toggle switch on your dash board and ground one side, run a wire from other side to terminal in step 4. Then you can turn on the fan any time you want to.

I used a Honda Fan Temp Switch, with a thread adapter for my Chev 350 mounted onto of the Tremostat housing. Its fun on a negative ground curcuit. Its a cheap temp switch, and last forever.. Better than the Bosch one to.. We also hooked the fan up to a Ignition power source, on a 30 AMP relay..

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